Optional trait methods for implementing the atomic_enable and
atomic_disable callbacks of a CRTC.
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
---
rust/kernel/drm/kms/crtc.rs | 88 ++++++++++++++++++++++++++++++++++++-
1 file changed, 86 insertions(+), 2 deletions(-)
diff --git a/rust/kernel/drm/kms/crtc.rs b/rust/kernel/drm/kms/crtc.rs
index 131d10505ba07..9026d0911aa86 100644
--- a/rust/kernel/drm/kms/crtc.rs
+++ b/rust/kernel/drm/kms/crtc.rs
@@ -76,8 +76,16 @@ pub trait DriverCrtc: Send + Sync + Sized {
},
helper_funcs: bindings::drm_crtc_helper_funcs {
- atomic_disable: None,
- atomic_enable: None,
+ atomic_disable: if Self::HAS_ATOMIC_DISABLE {
+ Some(atomic_disable_callback::<Self>)
+ } else {
+ None
+ },
+ atomic_enable: if Self::HAS_ATOMIC_ENABLE {
+ Some(atomic_enable_callback::<Self>)
+ } else {
+ None
+ },
atomic_check: if Self::HAS_ATOMIC_CHECK {
Some(atomic_check_callback::<Self>)
} else {
@@ -170,6 +178,34 @@ fn atomic_flush(
) {
build_error::build_error("This should never be reachable")
}
+
+ /// The optional [`drm_crtc_helper_funcs.atomic_enable`] hook.
+ ///
+ /// This hook will be called before enabling a [`Crtc`] in an atomic commit.
+ ///
+ /// [`drm_crtc_helper_funcs.atomic_enable`]: srctree/include/drm/drm_modeset_helper_vtables.h
+ fn atomic_enable(
+ _crtc: &Crtc<Self>,
+ _old_state: &CrtcState<Self::State>,
+ _new_state: CrtcStateMutator<'_, CrtcState<Self::State>>,
+ _state: &AtomicStateMutator<Self::Driver>,
+ ) {
+ build_error::build_error("This should never be reachable")
+ }
+
+ /// The optional [`drm_crtc_helper_funcs.atomic_disable`] hook.
+ ///
+ /// This hook will be called before disabling a [`Crtc`] in an atomic commit.
+ ///
+ /// [`drm_crtc_helper_funcs.atomic_disable`]: srctree/include/drm/drm_modeset_helper_vtables.h
+ fn atomic_disable(
+ _crtc: &Crtc<Self>,
+ _old_state: &CrtcState<Self::State>,
+ _new_state: CrtcStateMutator<'_, CrtcState<Self::State>>,
+ _state: &AtomicStateMutator<Self::Driver>,
+ ) {
+ build_error::build_error("This should never be reachable")
+ }
}
/// The generated C vtable for a [`DriverCrtc`].
@@ -1004,3 +1040,51 @@ fn vtable(&self) -> *const Self::Vtable {
T::atomic_flush(crtc, old_state, new_state, &state);
}
+
+unsafe extern "C" fn atomic_enable_callback<T: DriverCrtc>(
+ crtc: *mut bindings::drm_crtc,
+ state: *mut bindings::drm_atomic_state,
+) {
+ // SAFETY:
+ // - We're guaranteed `crtc` is of type `Crtc<T>` via type invariants.
+ // - We're guaranteed by DRM that `crtc` is pointing to a valid initialized state.
+ let crtc = unsafe { Crtc::from_raw(crtc) };
+
+ // SAFETY: DRM never passes an invalid ptr for `state`
+ let state = unsafe { AtomicStateMutator::new(NonNull::new_unchecked(state)) };
+
+ // SAFETY: We're in an atomic enable callback, so we know that both the new and old state are
+ // present
+ let (old_state, new_state) = unsafe {
+ (
+ state.get_old_crtc_state(crtc).unwrap_unchecked(),
+ state.get_new_crtc_state(crtc).unwrap_unchecked(),
+ )
+ };
+
+ T::atomic_enable(crtc, old_state, new_state, &state);
+}
+
+unsafe extern "C" fn atomic_disable_callback<T: DriverCrtc>(
+ crtc: *mut bindings::drm_crtc,
+ state: *mut bindings::drm_atomic_state,
+) {
+ // SAFETY:
+ // - We're guaranteed `crtc` points to a valid instance of `drm_crtc`
+ // - We're guaranteed that `crtc` is of type `Plane<T>` by `DriverPlane`s type invariants.
+ let crtc = unsafe { Crtc::from_raw(crtc) };
+
+ // SAFETY: We're guaranteed that `state` points to a valid `drm_crtc_state` by DRM
+ let state = unsafe { AtomicStateMutator::new(NonNull::new_unchecked(state)) };
+
+ // SAFETY: We're in an atomic commit callback, so we know that both the new and old state are
+ // present
+ let (old_state, new_state) = unsafe {
+ (
+ state.get_old_crtc_state(crtc).unwrap_unchecked(),
+ state.get_new_crtc_state(crtc).unwrap_unchecked(),
+ )
+ };
+
+ T::atomic_disable(crtc, old_state, new_state, &state);
+}
--
2.48.1
